Resin-impregnated substrate

Abstract

A resin-impregnated substrate having a high heat resistance at a high temperature under soldering conditions and a small linear expansion rate is provided. The resin-impregnated substrate can be obtained by a method comprising the steps of immersing a sheet comprising an aromatic liquid-crystalline polyester fiber in an aromatic liquid-crystalline polyester solution containing an aprotonic solvent and a liquid-crystalline polyester comprising 10 to 35% by mol, with respect to the total repeating units of the polyester, of at least one repeating unit selected from the group consisting of a repeating unit derived from an aromatic diamine and a repeating unit derived from an aromatic amine with a phenolic hydroxyl group; and removing the solvent.

1. A resin-impregnated substrate obtainable by a method comprising the steps of:
 immersing a sheet comprising an aromatic liquid-crystalline polyester fiber in an aromatic liquid-crystalline polyester solution containing an aprotonic solvent and a liquid-crystalline polyester comprising 10 to 35% by mol, with respect to the total repeating units of the polyester, of at least one repeating unit selected from the group consisting of a repeating unit derived from an aromatic diamine and a repeating unit derived from an aromatic amine with a phenolic hydroxyl group; and 
 removing the solvent. 
 
     
     
       2. A resin-impregnated substrate according to  claim 1 , wherein the aprotonic solvent is a solvent containing no halogen atom. 
     
     
       3. A resin-impregnated substrate according to  claim 2 , wherein the aprotonic solvent is a solvent having a dipolar moment of not less than 3 and not more than 5. 
     
     
       4. A resin-impregnated substrate with a conductive layer, which comprises the resin-impregnated substrate according to  claim 1  and at least one conductive layer placed on at least one side of the substrate.